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91.
92.
M.V. Madhubabu R. Shankar T. Krishna Y. Satish Kumar Y. Chiranjeevi Ch. Muralikrishna H. Rama Mohan Satish S. More M.V. Basaveswara Rao Raghunadh Akula 《Tetrahedron: Asymmetry》2017,28(12):1803-1807
A convergent approach towards the synthesis of the 2-alkyl-substituted tetrahydroquinoline alkaloid (?)-cuspareine via enantiospecific construction of the (R)-benzyl 2-formyl-3,4-dihydroquinoline-1(2H)-carboxylate. We have achieved an efficient enantiospecific synthesis of (?)-cuspareine starting from known key starting materials. The reactions employed for individual transformations are simple and high yielding, and the strategy could potentially be easily extended. 相似文献
93.
Kinetics of polymerization of methyl methacrylate initiated by Mn3+/1,2-propanedlol has been investigated in aqueous sulfuric acid at the temperature range of 25–35°C. The rate of polymerization (Rp) and the rate of manganic ion disappearance (-RMn) have been computed. The effects of organic solvents, certain cationic and anionic detergents, added electrolytes on the initial rate of polymerization, and maximum conversion have been examined. Depending on the kinetic results, a reaction scheme has been suggested involving the formation of a complex between Mn3+ and the alcohol, which subsequently decomposed in an unimolecular step to generate the initiating free-radical which initiates polymerization and termination of the growing polymer chain by metal ion. 相似文献
94.
N. Pongali Sathya Prabu M. L. N. Madhu Mohan 《Journal of Thermal Analysis and Calorimetry》2013,113(2):811-820
Novel homologous series of supramolecular hydrogen bonded liquid crystals have been investigated. Hydrogen bonds are formed between p-n octyloxy benzoic acid and various p-n alkyloxy benzoic acids whose carbon chain length varied from pentyl to dodecyl. These complexes are characterized by Fourier transform infrared spectroscopy, polarizing optical microscopy (POM), and differential scanning calorimetry (DSC). Phase diagram is constructed from POM and DSC data. The order of the phase transitions is determined by Navard and Cox ratio (N R). Characteristic phases like nematic, smectic C, and smectic F are identified. A new smectic ordering observed in this series is investigated by constructing phase diagram obtained from two binary mixtures of the present homologs. Inter-digitation of lamellar layers is observed to be one of the reasons for the occurrence of new smectic ordering. Optical tilt angle in smectic C phase is fitted to a power law. The magnitude of exponent of the power law is found to concur with the Mean Field theory predicted value. 相似文献
95.
The cross-Cannizzaro reaction of m-phenoxybenzaldehyde and m-bromobenzaldehyde with aqueous formaldehyde in a two-phase system can be intensified and made more selective by using hydrotropes; cationic surfactants do not improve selectivity. 相似文献
96.
Sidhanath V. Bhosale Mohan B. Kalyankar Santosh V. Nalage Dattatry S. Bhosale Swati L. Pandhare Trupti V. Kotbagi 《合成通讯》2013,43(5):762-769
A simple one-pot synthesis has been developed for the synthesis of 2,4,5-trisubstituted imidazoles using an efficient and recyclable MoO3/SiO2 solid acid catalyst by condensation of benzil or benzoin, benzaldehyde, and ammonium acetate in acetonitrile as a solvent. Using this solid catalyst, the reactions could be carried out under mild reaction conditions with very good yield of imidazoles, up to 95%. This catalyst could be recycled very easily, which makes this methodology environmentally benign. 相似文献
97.
Metal-free synthesis of substituted imidazole [1,2-a]pyridines from deprotective N-(prop-2-yn-1-yl)pyridin-2-amines in water is elucidated. Electron releasing substituents on pyridine ring provided pure products in quantitative yields without separation by column chromatography. 相似文献
98.
R. Anjibabu Samaresh Sau B. Jagan Mohan Reddy Rajkumar Banerjee B.V. Subba Reddy 《Tetrahedron letters》2013
A variety of aldehydes undergo a smooth coupling with (4-methylcyclohex-3-en-1-yl)methanol in the presence of 2 mol % of phosphomolybdic acid in dichloromethane to afford 3-oxabicyclo[3.3.1]non-7-ene in good yields through 3,5-oxonium-ene cyclization under mild conditions. The use of inexpensive, nontoxic, and readily available heteropoly acid catalyst makes this method simple, convenient, and environmental-friendly. 相似文献
99.
Kandasamy Jothivenkatachalam Singaravelu Chandra Mohan Paramasivan Natarajan 《Research on Chemical Intermediates》2013,39(7):3371-3386
Cobalt(III) ammine complexes coordinated to carboxylic acids are classic examples showing photoredox reactions originating from the ligand to metal charge transfer excited states. Cobalt(III) pentaammine complexes coordinated to unsaturated carboxylic acids as ligands were synthesized and characterized by spectroscopic methods. The photolysis of these complexes produces a carboxylate free radical. This free radical undergoes further transformation to form organic photoproducts. The organic photoproducts were characterized by spectroscopic methods. The nature of the decomposition products from the organic photoproduct was examined in detail. The quantum yields were also determined. The photochemical reactions have the potential to produce novel compounds from the decarboxylation of unsaturated acids, which shows interesting reaction pathways. 相似文献
100.
M. Chandra Sekhar N. Nanda Kumar Reddy B. Venkata Rao G. Mohan Rao S. Uthanna 《Surface and interface analysis : SIA》2014,46(7):465-471
Titanium dioxide (TiO2) thin films were deposited onto p‐Si substrates held at room temperature by reactive Direct Current (DC) magnetron sputtering at various sputter powers in the range 80–200 W. The as‐deposited TiO2 films were annealed at a temperature of 1023 K. The post‐annealed films were characterized for crystallographic structure, chemical binding configuration, surface morphology and optical absorption. The electrical and dielectric properties of Al/TiO2/p‐Si structure were determined from the capacitance–voltage and current–voltage characteristics. X‐ray diffraction studies confirmed that the as‐deposited films were amorphous in nature. After post‐annealing at 1023 K, the films formed at lower powers exhibited anatase phase, where as those deposited at sputter powers > 160 W showed the mixed anatase and rutile phases of TiO2. The surface morphology of the films varied significantly with the increase of sputter power. The electrical and dielectric properties on the air‐annealed Al/TiO2/p‐Si structures were studied. The effect of sputter power on the electrical and dielectric characteristics of the structure of Al/TiO2/p‐Si (metal‐insulator‐semiconductor) was systematically investigated. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献